Gate or door operating mechanism



Juin 14, 1927.

T. E. RoBlNsoN GATE on Doon OPERATING MEGHANISM Filed Jan. 17, 1924 4 Sheets-Sheet l Jme 14' 1927 TQ E. ROBINSON GATE 0R DOOR OPERATING MECHANISM Filed Jan. 17, 1924 4 Sheet's-Sheet 2 June 14.1927. l

T. E. ROBINSON GATE OR DOOR OPERATING MEGHANISM Filed Jan. 17, 1924 4 Sheets-Sheet 3 `une 14, 1927.

T. E. RCBINSON GATE oR Doon OPERATING MECHANISM Filed Jan- 17. 1924 4 sheets-sheet 4 While the elevator Patented June 14, 1927.y

y THOMAS E. RonINsoN, or PHIL,

DELPHIA; PENNSYLVANIA.

Gern on *noon oPnRArIneivinciiANIsi/i.

" `inspireman'inea January i7, 1924. serial No. 686,736.

y My inventionl relates to sliding gates, with particular reference to gatesand doors into freight elevator shafts'. l l i f The purpose o'fiiiy invention is to provide ay novel form of sliding gate that is particularly Welly adapted to meet the needs of service; va gate that will mat'ically stay open to any f desired extent is atthe gate,v that will gentlyV and automatically close to any predetermined extent when the elevator moves Vfrom the gate, and thatvvill be heldin closed ".positionat other times,fas by its own Weight,

.even when, as lqprete'r,

closed. v Y A further purpose is zto render the counter- Weighting inetfective when J the elevator is not in position at the floor protected by 'the gate vto, provide torautomaticr closing and,

diiicult opening then. n l y I l Y A lfurther purpose is to couiiteriveight ditferent-,endsof a' ytelescoping gate upon ditterent leverages and to limit the telescopic openingV ot thedoor.`T Y l A further purpose isy during closure to gradually transfer part ot the-eliectivepull of the gate upon the Counterweight from a larger to asinaller leverage so as to automatically stop the i y erablyprogressively increasing) the counter- Weighting of an initially under-counter- Weighted gate. y y l A further purpose is to provide for gentleness' of automatic closure by increasing the effect of the counteriveigliting as thegate approaches its position ot closure. l i A further purpose is to have'the counter- Weighting connection ratcheted during antol tly matic closure of the Vgate When the elevator is not'at the floor protected by the gate so as vto prevent 'any rebound of the gate lfrom its position ot closure, changing the under counteriveighting as the gate approaches l its position of closure to.over-counterweighting for rapid yet gentle deceleration to closure.

A yfurther purpose is toV provideineans effective when the elevator is not at the gate whereby the shaft is locked iroin turning in opening direction and tree ,to turnin 4 closing direction, permitting the gate togenai'itoniatically close when the elevator leaves the gate and` then to `ble held shut by the entirepull toward closure. i. Y A furtherv purpose is to provide `a sliding easily open, auto-` isk not Vlocked gate by'increasing (prety gate normally tending to close and counterii-'eighted. With selective means, controlled by thepos'ition oit'tlie elevator, vtor stopping closure or checking 'opening movement ot the coiinteriveight K1A, further purpose is to provide a constant pull otthe gate toward closure (as by its own or other Weight) and to partially counterbalance this pull when the elevator is at the gate to permit easy opening with latch (preferably ratchet) holding ot the gate in open (preferably progressively opening) positions. f i

A further purpose is to apply the normal pull oit' the gate toward closure and a par:

`tially balancing, oppositely countervveiglit` ing vpull yto* a rotary-shaft controlled directly or indirectly by ratchets so astocheck movement dueto the ynormal.pullvvhen theelevator is at the gate, holding the gate in any position to which it has been raised, and to release the gate and to malte the pull ot the counterweighting upon the gate'ineffective to vhelp openingmovement ot the gate when the elevator is not at the gate, -so that `the normal pull of the gate will close it and the absence of counternf'eighting Will malte it diiiicult to open. A i,

. A further purpose'is to apply the normal closing' pull or' a gate toward .rotationot a shaft, and the .counterweighting for the gate toward the rotation ot' a shatt,preterably lthe opposite rotationof the same shaft, and

to stop either rotation by'iatchets. (in the preferred form `oppositely Jfacingratcliets on the saine shaft) and to determine `which ratchet shall be operative by the' position of the elevator.

` A turtherpnrpsoe is ytoprov-ide an -ad- .l vantageous and novel kratchet and pulley vmechanism upon ay eountcrb'alancing,shafty `for an elevator gate,`

I have shown afeiv only 'further purpose is te-.use variant`levericularly because they Well `Figure `1 is a rontelevation of a vertically sliding collapsible gate in position ot closure somewhat above the door line, the fame being sectioned in correspondence With line l 1 of Figure 2.

Figure 2 is a. section upon line 2-2 oi Figure 1, a part of the guide box being eliminated so as to show the gate.

Figure 2l is a fragmentary section corresponding to Figure 2 but showing a second t'orm.

Figure 3 is a vieu7 corresponding to Figure 1 but with the gate open.

Figure 4t is an enlarged detail from Figure 1, showing operating mechanism, but for the sake ot clearness omitting the sprocket chain and counterweight, the parts being shown in position when the elevator is not at the floor.

Figure 5 is a section ot' Figure 4 taken upon the line Figures 6 and 7 are somewhat diagrammatic front elevations of modified forms.

Figure 7u is a fragmentary t'ront elevation of another form.

Figure 8 is an enlarged detail from Figure 7 Figure S.L is a section, in slightly different position from that in Figure 8, ot the structure seen in Figuren.

Figure 9 is a section of .Figure 8 taken upon the line 9 9.

Figure l0 shows diagrammatically another lorm.

In all ligures like numerals refer to like parts.

Describing in illust-ration and notin limitation and referring to the drawings,-

My invention linds its widest application in use With freight ele y'ator gates sate-guarding the elevator shat't while the tire doors are open and the elevator car away.

lVhcnever there is not ample head room for a vertically sliding gate it is desirable to have the gate collapsible so as to occupy very little vertical height when in raised position and the gate shown in Figures 15 Yis ot this type. lVliile I have illustrated the main it'orm as oi the. collapsible type, it is to be understood that many vfeatures ot the invention are equally applicable to gates that do not collapse and to doors for many purposes other than the elevator shaft use suggested The. Word gate as used herein Ais intended generally to apply also to doors Wherever its setting permits such generic use. In special cases, Where there is plenty of head room, there may be no particular advantage in having the gate collapsible, and I illustrate the invention diagrammatically operating non-collapsible gates in Figures 7 and 10.

The collapsible gate 15, illustrated iu Figures l-S, slides vertically'in guiding runivays 16 at opposite sides of th-e elevator opening 17. The floor-line, Wall adjacent the elevator shaft, and toe-board at the top of the opening are shown, respectively, at 18, 19 and 20.

The gate is formed of strips 21 collapsibly latticedY upon pivot pins 22 and 2?), similarly to lazy tongs and stopped 'lron'i extension beyond the limit shown in Figure l by means ot lateral co-operating links 211- and 25, av suitable stop 26 on each pair of links 24, ot' the latticewvorl. The precise Way ot limiting the extension of the lattice is obviously not material. there lateral links 21, 25 are used, their extreme spread should be very materially less than 180 closure.

The operating and control mechanism of the gate is duplicated upon opposite sides so that it will be sutlicient to describe one side, the same description applying to both ff sides.

The double sprocket Wheel 27 is pivotally mounted in the upper framework ot the doorway upon a shaft 28 and by means ot chain 29 and counterweight 30 supports and positions the gate.

The double sprocket wheel comprises Wheels 81 and 32 ot' different diameters, preferably formed as tivo separate castings and locked 'lrom relative turning in any convenient Way, such as by longitudinally interlocking hubs seen at 33 and 3st in Figure 5. The separate castings permit intertitting and use ot different proportions or sizes of sprocket Wheels to suit the requirements ot ditlierent. sizes, Weights and arrangements of doors, and Without changing ratchet dimensions.

rIhe gate heilig collapsible, the top oi the gate does not have as large range of travel as the bottom, and this is taken care ot' by having the supporting chain 53.7 l'rom they smaller Wheel tast-cned to the top oll the gate and the supporting chain 3G from the larger wheel fastened to the bottom oi the gate. I have had great success with a ratio ot speed between the top and bottom of .l to 2, using a. gate Whose extended height is just twice its height when collapsed, but oil course recognize that this ratio need not be maintained, even with the form of collapsing gate shown in Figure 1, as the ratio ot' tull length and collapsed heights could be greatly varied and the gate need not be fully collapsed. In order to avoid the need for two counteryveights or for running one chain from the sprocket Wheel Without direct coun tern'eighting, I prefer to use a single chain and to support a single counter-weight 30 from a pulley 37 rolling upon the chain. The counterweight preferably operates Within a suitable guide box 38.

In order that the gate may not open easily when the elevator is not at the floor. I prdvide ratchet mechanism locking the double 25 limiting the relative angular spread to insure easy *sprocket Wheel from turning in such .direcf engagement with the `39`upon the radially 'loosely pivoted on rod 43.

Ation as to openthe gate during the periodthe elevator is not at'the floor; with the intent and eifect to neutralize the partial counterweighting of the weight' 30. If the gate be now lifted, no benefit is secured from the counterweighting, If lifted from the top the rentire weight must be lifted. If lifted from the bottom, the weight ,will not be thatof the entire Vgate at the start, owing to inevitable lost motion, `but as the lost motion is `taken up the weight will increase progres sively until the entire weight is being lifted.

lf released the entire weight lifted tends to `drop the weight' toits former position;

the toe44` of the pawl operating mechanism is the pushcam) presses the 'rod46 outwardly, .permitting the pawl` to engage "elevator `is atthetloo-r anvsuitabl'e part of the car y(not shown) "engagesthe shoe 48 the ratchet, lbut when the [pressing it :inwardly `against the action ot the spring 47 and holds the pawl away from its ratchet. i. f This ratchet mechanismy serves not `only to 'make it'hard'yet possible (by lifting the l Vuntil balanceis same rod 43.

Y fromA turning `in closing weight of the gate) to open the gate` when the elevator is not atthedoor, receiving no 'help from the counterweighting, but allows movement of the counterweight effected when the gate falls. Other ratchet mechanism, operative when the elevator is at the `pate 'and then only, prevents the doublesprocket wheel normall'7 direction when the elevator is 'at the gate but permits the gate to be opened and, when opened, to stay open automatically wherever upward pulleys (sprocket wheels) are used together,

as 1s the rcase vfor collapsible gates, itis convenient to `form ratchet'teeth 49fori this second ratchet upon the radially-extended rims 50 and '51 of the sprocket wheel 3l. Pawl 52 may The lowerend of thepawl pawl toward. engagement with its ratchet. The sam-e operating device,here push cam 45 on sliding rod`46, may engage the toe 53 of the Vpawlpholding Vit'fr-.om engagement .with its ratchet except when the car isat. the gate. f

weights the In view of lthe desirability yto standardize as far aspossible'the-parts of the equipment,

` a earn, and `preferably la push cam 45 carried by a sliding rod 46 is adapted tok engage A-to hold the pa-wl fromI engagement `with the ratchet. VNormally the 'spring 47 (wherethe attachment.V in the collapsible gate there would be apequal' pull upon `the Igate at- V `tachments at top and bottom .at all inter# set and, because of release of this ratchet, automatically closesl as the elevator leaves the l gate. the ,attachments `which disproportion is reduced'as the gateapproaches its lowe'rniost position. y When Wheren f two valso loosely pivot upon the -tion of over-counterweighting.

and of the difference of the requirements inpractice `making desirable any one .off/a number of ratios l ameters of the sprocket :wheels without any variation in'y the ratchet mechanism," l .ra-

gate arepulling upon different leverages cor` responding to the `radii of the two sprocket `wheels and the counterweightis operating upon `corresponding leverages equal at each sprocket wheel to the leverage ofthe gate Ifthere` were no lost motion proxiinately mediate positions of the gate with a maintained ratio of lifting `movement suchfthaty the complete collapse of the s gate at the top would bring all of the weight upon the lowergattachmentoperating on the longer leverage and thatfthe extreme bot-tomof the movement owing to the limitation of op'enl ing .movement ofthe gate all of the weight wouldbe taken immediately upon the upper between 'the effective di `variation in the sizesof y attachmentY operating about the shorter" leverage;

' As the presence of lost motion isinevita-` v ble,l however, starting from 'the position seen in Figure l the collapsing proceeds somewhat morerapidly at the bottom than atthe top with opening movement of the gate allowing agreater proportionate pull upon the attachments at the bottom of the gate.v Foi-the' same 4reason when the case has been `completely collapsed at its `upper position and starts downwardly, a relatively llO larger part ofthe weight is 4sustained by to the bottoniof the gate the gate reaches the pointwh-ere the farms 24 and 25 lock against-further opening and the chains Sehecome slack because they are moving downwardly at a Vfaster rate the chains 35 without,corresponding exten-v sion of the gate, the weight of the gate which has been .divided between the two leverages corresponding toy the two leverages upon which the counterweight `is ,operating; is

linallv' rested `wholly yupon the shorter leverof this the counterweighting quickly brings the gate to rest without necessity for Stops engaging the gate. The gate may thus be made to stop at any predetern'iined point above the floor. The distance which the gate will travel before stopping' after the leverage exerted by it has been shifted from the divided leverage to the short leverage ot the small pulley depends upon a number of factors including the amount of undercounterweighting and the amount of lost motion in the gate structure.

Since the latch 52 holds the gate in suspensions in any position which it has reached during upward travel while the elevator car is at the floor, the gate need not be completely raised to any catch and when the ratchet is released whether by reason of movement of the elevator car or separatelyv the weight of the gate will cause it to close from the position to which it has been lifted. The latclril olf-ers no resistance to this movement.

Willen the elevator car. is not atthe tloor the latch 52 i`s released, but the latch 4t2 is in engagement with its ratchet preventing downward movementof the counterweight. As a. result no benefit from the counterweighting is had in lifting the gate and the entire weight of the gate must be lifted in opening.

I preferablyT provide a safety buffer between the eounterweight and the operatingT mechanism. This butler is merely a safety device and guard for the operating mechanism and normally7 will never be engaged by the counterweight.. The gate is stopped not by engagement between the counterweight and buffer but by the rapid deceleration due to the shifting from und'er-counterweighting to over-counterweighting a little before the closing position has been reached. The closingv position is normally7 about six inches from the floor. This capacity for coming to rest without striking a definite stop does not of course interfere with the use of the buffer as a stop or any other stop for the gate if desired.

In Figure 2 separate chains are used and either of the chains, here 36, is not attached to the counterweight but is loose at the end nearest the counterweight. It passes over a sprocket- 312 which is rotated by sprocket 32 and both of which are free from ratchet teeth. These are located at 49 and 39. respectively upon separate ratchet discs 312, 322 rotating with the sprockets. This construction. inferior to the other-,is shown for the purpose merely of indicating that my broad combination is between the. elements` so coupled as to operate at theV same speed or selected ratio of speeds (preferably but not necessarily rigid with the same shaft) and preferably with al counterweight pulling upon both chains; but that for its broader features my invention does not require the correlation of parts so desirable in my preferred form in the attainment of compactness, simplicity and chcapncss.

The modified form shown in Figur-e 6 has precisely the same operating mechanism as in the first form, the only difference being in the form of collapsible gate, shown as comprising overlapping, oversliding gates and 56.

The upper gate, 55, having a smaller range of travel is supported from the smaller sprocket wheel, and the lower gate. 5V. having a wider range of travel, from the larger sprocket wheel. Any suitable stops 26 here shown as aligned cars, cause the upper gate section 55 to support the lower section at the limit the relative extension of the gates and result in gently bringing the gate to rest in automatic closure by throwing the entire support of both gates upon the chain 35, effectively changing the degree of counterweighting from under-counterweighting to over-counterweighting. A spiral spring 262 affords a resilient butler between the parts, making the shifting of the countcrweighting gradual.

Evidently some of the features of my invention are of general application and are separately available even where other features are not applied. Such, for example. are the locking ot the counterweighting so as to eliminate the counterweight as an assistant in lifting the gate, whether the locking be controlled by automatic means or not; the automatic shift from latching the gate in its raised position to latching the counter-weight, and vice versa, whether the latching of gate and counterweight be progressive or require a certain predetermined and reasonable full movement for the latching to be effective; and the shifting of the counterweighting from under-counterwcighting to over-counterweighting.

The suitability of the lirst two of these for general use is obvious enough not to rcquire illustration. I have thought it best, however, to illustrate another mechanism for accomplishing the shift in counterweighting in order that its further applicability may be made more clear.

Though my invention finds its best application in conjunction with collapsible gates, sprocket wheels of dierent size to cause travel at different rates and stop mechanism to limit the extension so all of the weight comes upon the top of the gate, making the shift in counterweighting to the best advantage on the gate side of the pulley (sprocket) support, the same general principle can be applied to doors which are not collapsible and the illustration in Figures 119 is intended to show this as well as to show the fact that the leverage of the gate upon the counterweight may be reduced or the lever- Sli lll)

lol:

sulting as Vbefore in gentle closure. i ratchet mechanismV iSwvi-rtually the same as l forms n except that Vthe sprocket member is shown as an integraljca'st- `a larger leverage 58 at an intermediate .point ing increased yto age of the countervveight upon the gate'may be increased at WilliV tol secure' the results sought.` i l i t The ,method et counterweight shifting shown in Figures 7,- 8 and Q and in Figures 72" and 8a is not confined to use in conjnncv tion With ratchet gate structures but canbe used to accentuate the differences in leverage with collapsible gates. i t

Inl Figures 7-9 anon-collapsible gate 55 is shown, which may prove preferable on ac count of its lou7 cost where the head room is ample. f l

The ,sprocket wheel member 27 yhas its sprocllret teeth arranged in the form of a camv sprocket thread 57 upon which thechain 36 windsa-t oneendas` it unwinds att-he other.

l This thread deepens to a shorter radius position 58 when the gate ris nearly in its closed 'position von the gate side thereby lessening the arm of theturning moment exerted bythe gate and, increasing the coui'iterbalaneing effect-off the `Weight,

in the preceding ing and the ratchet'members() at opposite sides thereofl are shown as oit the same size with teeth 6l like ordinary gear teeth. x

ln Figures 7a and 8*l the path 57 ofthe chain instead ot being more deeply grooved at 58 upon the side* finally engaged by they portion 36 ,of the supporting' chain, to reduce the final leverage of the gate is given from Which the portion 29 `ot, the -chain stretches to the counterweight so as to increase the leverage of theicountervveight at this time when the gate isdownfobtaining the same relativeetfect of shifting thecountervveighting from under-counterweighting to overeounterweighting'. n 'Y In all of' the preceding Jiorms theV Weights of the i gates supply a resilient orcenormally pulling the gates toward closure, radapty ingttliem to automatic closure when desired, i ordinarily when4 an elevator car, lea-ves the toward closuremust be added,'asiillustratedy Vin Figure 10.

. In'FigureflO- is shown la. pair of gates, 62 and 63 respectively,- in position of closure,v

Each gate is independent in its action, eX-

cept as each may press against the other -in closed position, and a single gate could be used. f Where two are used the gates openand close oppositely with respect to one another' and are shown provided With supporting 1ollers64, traveling ontrack 65.

They operate identically the same, so'that` only one need bedescribed. i

The Weight 66 acts in the same Way as gravity, y exerting a constant closing v,pull flexible conneetionv passing over through pulley` to a lug 69 upon the gate.` `The counterweight 30 operates through.r chain 29 i passing over the sprocket Wheel member 27 to under-counterweight the pull toward closure While the elevator is at the door, during opening' of the door and during automatic closure until near closure when the undercounteriveighting is automatically changed to over-counterweighting by a shift in the leverages aft Which the constant pull and counterweiglit operate to give gentle closure. The shift is accomplished here as in Figures 7, 8 and 9.

It will be obvious that in allot lthe forms shown and Vin order to get the full benefit oty my invention there is the combination ot a door pulling toward closure to effect automatic-closurewhen the elevator leaves the iioor, a partial counterweighting of theA pull n when the elevator is at the floor to permit easyV opening and gentle closure, a material increase of the effective. counterweighting neark closure to make the closure 'much more gentle, ratchet mechanism making the counterweighting inoperative to assist in opening (but not inoperative to oppose ur` ther closing movement) except When the door is closing or theelevator is at the gate thus making it hard but possible to open the gate when the elevator is not vat the' gate, and other ratchet mechanism'latcliing against rclosure Whenvthe elevatoris at the gate and .in-operative at other times, adapting the door to stay'open at any position at which it may be set When the elevator isat the door. p l

ln` view of my invention and disclosurey variations and ymodifications toglmeet inl p doubt-y less become evident toothersskilled in the y dividual vvhim or particular need Will artand l elaimall Asuch in soffar as they fall Vwithin the reasonable spirit and scope ot' my, invention.

Having thus described my invention, ywhat If claim as new` and desire tosecure by Letters Patentis:- t

The method of counterbalancing a collapsible gate having a tendency to move to one:direction,wliich consists in co'unterbalancing the gate at different points'upon dit;v

ferent leveragesand shiftingfthe pulls upon theftwo leverages so as to under'co'unter-` weight at'the start of closing movement and Y.

i to relatively increase the effect of the counterweighting against the` gate pull in final closing movement of the gate.

2. The method of counterweighting a collapsible gate having a resilient pull toward closed position which consists in counterweighting the forward end of the gate considered in closing movement about a. longer leverage than the rear end of the gate considered with the same direction of movement, selecting the counterweight to under counterweight when the gate is wholly or in part collapsed and part of the counter-weighting pull is being taken by the forward end of the gate and to overbalance the counterweight as compared with the pull of the gate when the collapsible gate approaches closed position.

3. rfhe n'iethod of counterweighting a collapsible gate having a continuous pull toward closing position; which consists in counterweighting spaced portions of the gate about pulleys having' different leverages, controlling the pulleys to operate them together, stopping the extension of the collapsible gate positively and selecting the counterweight to represent over-counterweighting when the gate is fully extended and is pulling on the smaller leverage ver 7 largely or wholly and under-counterweighted when the gate is partly collapsed and more of its weight is supported upon the larger leverage.

4. The method of operating a gate which consists in counterweighting the gate about pulleys, applying oppositely facing ratchet control to said pulleys, setting the ratchet to allow downward movement only of the gate and upward movement only of the counterweight when it is desired to prevent opening thereof, thus rendering the counterweighting ineffective to open the gate during this time. and releasing the cont-rol of the downward movement of the counterweight when it is intended to open the gate.

5. The method of operating a gate which consists in counterweighting the gate about pulleys. applying' oppositely facing ratchet control to said pulleys, setting the ratchet to' allow downward movement: only of the gate and upward movement only of the counterweight when it is desired to prevent opening thereof, thus rendering the counterweighting ineffective to open the gate during this time, and releasing the control of the downward movement of the counterweight and controlling the gate against downward movement thereof when it is intended to open the gate.

Gf The method of controlling an elevator gate adapted to drop into closing position which consists in supporting it by counterweighting adapted to permit it to fall to the closed position, controlling the counterweighting by ratchet movement in opposite directions and utilizing the elevator car to apply the ratchet to render the counterweighting ineffective when the elevator car is not in position at the door and reversing the ratchet control to' prevent downward movement of the gate in raised positions of the gate when the elevator car is in position at the gate.

7. The method of counterlnilancing a collapsible gate continuously pulled toward closing position which consists in limiting the extension of the gate, counterbalancing the gate at opposite ends upon diii'erent leve ages and shifting the leverage upon the counterbalance as the gate closes from 'divided pull at the'two ends to a pull at the end having smaller counterbalancing leverages so as to shift the counter-weighting from a condition of undercounterweight when the gate is open to a condition of equal,- ization of counterweighting or over-counterweighting when the gate is closed.

S. rlhe method of counterweighting and operatingl a vertically movable collapsible gate, which consists in supporting the gate by counterbalaneing the upper and lower parts, the leverage upon the counter-balance of the connection to the upper part of the gate being shorter than that to the lower part of the gate and collapsing the gate at the same time that it is raised.

9. The method of operating a collapsible vertically movable gate, which consists in supporting the gate at the top and bottom by counterweighting and operating about interconnected pulleys, the counterweighting for the upper part of the gate being smaller than that of the lower part of the gate and thus collapsing the gate as it is raised.

10. The method of operating a collapsible vertically movable gate, which consists in supporting the gate at the top and bottom by counterweighting and operating about interconnected pulleys, the counterweighting for the upper part of the gate being smaller than that of the lower part of the gate and the counter-weighting being less than the weight of the gate in the raised positions of the gate and ratcheting the pulleys to retain the gate in raised position.

11. The method of operating a collapsible vertically movable gate which consists in supporting the gate at the top and bottom by counterweighting operating about interconnected pulleys. the counterweighting for the upper part of the gate being smaller than that of the lower part of the gate and the counterweighting being effectively less than the weight of the gate in the raised positions of the gate, ratcheting the pulleys to retain the gate in raised position and automatically releasing the ratchet as the car leaves the position in front of the gate.

12. The method of operating a collapsible vertically movable gate at an elevator shaft, which consists in supporting the gate at the memos? top aadbaomby @Ounafwigiaing operiai ying about interconnected pulleys, the counterweighting vfor the upperl partV ofi the gate' being smaller thanl that fo'r the lower part of the gate, and thecounterweighting being effectively lessV in'the raised positions of the gate, ratchet-y ing the pulleys to retain the gate in raised position andilatching the eounterweighting so' as to render itA ineffective when a car leaves" the position opposite vthe gate.

13. The'method ofoperating a collapsible vertically movable gate at which consists in supporting the gate at the vtop and bottom by counter'weighting operating about interconnected pulleys, the counterweitghting for the upper part ofthe gate being smallerfthan that for the lower part of the gate and the counterweighting being eff-ectively'less than the weight of the gate in theraised posit-ions ofthe gate,` ratcheting tliewpulleysgto retainthe'gate' in "raised position, automatically releasing as a car leaves the position in front of the gate and ratcheting the-counterweighting so as to render it ineffective when a can leaves the position opposite the gate.

14. The method of easing the closing of a collapsible gate continuously pulled toward closing position, which consists in applying the counterweighting to the gate at different points movablewith respect to each [other during collapse and with different i au leverages and in shifting the leverage of one of the `parts while maintaining the leverage section during closing movement to shift the relative leverage ofthe counterweighting.

`17. In aV closure yfor elevator openings, a gate pulling toward closure, a rotary ratchet and pawl` against door.'l closure, and means rendering the ratchet and pawl inoperative when the elevator is not at the opening.

18. A gate pulling toward closure, a partial counterweighting of the pull, means for increasing kthe counterweighting in closure to over-counterweight before the position of closure is reached and means for holding the gate against upward movement dueto the over-counterwcighting.

19. In elevator apparatus,

than the weight of the gatean` elevator shaft,r

the ratchet leverages of the sections upona shaft adapted i to rotate, ai vertical sliding gate, con'i'iections` between thevgatey and thevshaft whereby the weight ofthe gateV tends toI turn the shaft in onel direction, meansk tending' to' turn i the shaft inthe other direction to partiallybal-- ance the turning tendency ofi the gate,

ratchet means engaging parts rotatable with c the shaft adapted to prevent the shaft from l turning in said other direction when the elevator is not at the gate and an automatic release' for' the ratchet controlled by the position of the elevator.` f

- 20. In elevator apparatus, al shaft adapted to rotate, a verticallysliding gate, connecs' tions between the gate and the shaft where` by the weight ofthe gate tends to turnthe shaft in' one direction, means tending to turn" the sha-ft in the other direction to under counterweight the gate, and ratchet means engaging parts rotatable with the shaft adapted to prevent the`v shaft from turning' in said first direct-'ion whenthe elevator is at the l`gate.` i In elevator apparatus, a vertically sliding gate, an under-counterweight therefor, a shaft for the counterweight, means operated by the elevator for making the un-y der-counterweight inoperative at desired positions of the elevator, and ratchet means engaging parts rotatable with the shaft inoperative when the 'elevator is not at the gate for holdingthe gate open.

22. In elevator apparatus,'a shaft adapted to rotate, a vertically sliding gate, connections between the gate and the shaft whereby the shaft must raise the gateif it turn in one direction, means tending to turn the shaft in. the other direction to undercounterweight the gate, and ratchet means locking the shaft from turning in direction to raise the gate when the elevator is not at the gate and locking the shaft from turning to close the gate when the elevator is at the gate.

23. In elevator apparatus, a'slidinggate pulling toward closure, a partial counterbalance therefor, with the gate to turn when the gate moves, a pawl therefor pressing toward ratchet engageinent and operating' means holding the loawl from ratchet engagement and adapted to be displaced engagement between the pawl and ratchet.

24. In a vertically sliding gate, a collapsible lattice,-means for raising and lowering the top, whereby the weightjof the lattice yholds it extended, and other means for raising and lowering the bottom.

25. A vertically sliding collapsible lattice,

`and mean-s for simultaneously raising or lowering the top and bottom thereof to rela tively different distances.

26. A vertically sliding collapsible lattice a shaft adapted to rotate, supporting gate,

between the shaft and the top connections a rotary ratchet movablev by the elevator to permit` and bottom respectively of the gate, tending to rotate the sha-ft to lower the gate, and an untler-counterweight for the gate.

27. A vertically sliding collapsible lattice gate, a Shaft adapted to rotate and agateoperating flexible connection supported thereby and on one Side Separately carrying the top and bottom respectively or" the gate and onl the other side loosely supporting an uncler-counterweight for the gate.

28. A vertically sliding collapsible lattice gate, a shaft adapted to rotate, a pair of wheels of relatively dill'lerentradius faStenetl thereon to rotate therewith, and a lexible connection over the Wheels supporting the top and bottom respectively ot' the gate on one side and supporting upon their other side an unclercounterweight for the gate.

29. A sliding.;` collapsible lattice gate pulling` toward closure and collapse, a shaft adapted to rotate, a pair ot' wheels of relatively clitferent radius mounted on the Shaft to rotate therewith, tiexble connections fromy one side of the wheels to the respective ends of the gate supporting the gate Ytroni collapse ancl closure, and an under-counter- Weight for the pull ot' the gate loosely carried by the flexible connection on the other side ot' the wheels and maintaining proper engagement between the Wheels and conncction.

30. In elevator apparatus, the combination of a gate pulling toward closure to ettect automatic closure as the elevator leaves the floor, a partial countern'eight tor the pull, means for increasing' the counter- Weighting near closure to make closure more gentle, ratchet mechanism makingthe connteriveighting inoperative when the gate is not closingand when the elevator is not at the gate to make it hard to open the gate, and other ratchet mechanism latching progressivelyv with opening,` movement and against closure when the elevator is at the gate and inoperative at other times.

THOMAS E. ROBINSON. 

